Friction device.



M. J. L. TOWLER.

FRICTION DEVICE.

APPLICATION FILED NOV. 21, 1908.

Patented Nov. 24, 1914 &

f/n/mfar flarz'mz'lz'an TIL 752026) Wz'fnesses WW mm W UNITED STATES PATENT orrron.

,MAXIMILIAN J. L. TOWLER, or nn'rnorr, MICHIGAN.

FRICTION DEVICE.

Application filed November 21, 1908. Serial No. 463,776.

To all whom it may concern i Be it known tl12Lt.I,.MAXIMILIAN J. L. TowLnR, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Friction Devices, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to that class of friction devices more particularly designed for use in connection with hoisting apparatus for the purpose of holding the load from accidental release, while permitting both the raising and lowering thereof.

The invention consistsfirst, in the peculiar construction of a friction shoe, and, further, in the construction and arrangement of the same, in relation to the holding apparatus, as more fully hereinafter set forth.

In the drawings Figure 1 is a sectional elevation of the apparatus; Fig. 2 is a section on line mew, Fig. 1; Fig. 3 is an elevation of one of the shoes; Fig. 4f is a section similar to Fig. 2 illustrating a modified construction; and Fig. 5 is a similar view showing another modification.

In general construction the apparatus comprises a rotary member, such as the shaft A, on which is mounted a rotary friction member B engaging friction shoes 0 in a. supporting bearing D. The member B formsin effect a journal for the shaft A and theshoes C a bearing for said journal which, when the shaft is driven by a force reacting on the shoes within the .limiting angle of friction, will operate as a lock. On the other hand, ifthe driving force reacts upon the shoes without the angle of friction, rotation of the shaft and member B is permitted. WVhere the device is employed for a hoisting drum, such as E, mounted on the shaft A, it is so organized that the load reacting tangentially upon the drum, andthrough the latter upon the shoes G, will be within the angle of fric tion, while the driving member, such as the gear wheel F of larger diameter than the drum E, will react upon the shoe outside of the angle of friction.

It is desirable to reduce the size of the journalB, and to this end, in certain constructions heretofore used, wedge-shaped friction shoes have been employed. These permit of materially reducing the diameter of the member B. while still maintaining the Specification of Letters Patent.

reactive force from the drum upon the shoe 1 within the angle of friction, but 111 practice it has been found that such shoes lose their efliciency. This is due to the fact that. the contacting surfaces of the shoe and the rotary member B will be frictionally worn so as to lose their original shape, the effect being, to form a series of minute annular grooves. Thus, instead of having an oblique bearing upon the member B, the surface of the shoe gradually assumes the shape ofa stepped bearing, with the effective frictional surface parallel to the axis of rotation. With the present :construction this dilliculty is avoided by forming the bearing faces of the shoe substantially parallel to theplane of rotation and to the axis, and

by providing a wedgewhich operates upon the shoe to force the same into frictional contact with the wheel. Such a construction will be just as; efi'ectuous at the start as the wedge-shaped shoe, and will also maintain its efficiency unimpaired by the wearingiof the parts. i

As preferably constructed the shoes G are formed of two separate friction members G and G, which have stepped surfaces contacting with correspondingly formed surfaces in the wheel B. The surfaces H, H, H are parallel. to the plane of rotation, while the surfaces I, I, I are parallel to the shaft A. Intermediate the members G G is a wedge .I, this wedge being supported in the bearings 1) upon the pins K. With tive force operating through the wedge will be divided into two parts, one forcing the members G (1% against the friction facesH, H, H while the other simultaneously forces said members against the cylindrical surfaces I, I, I Any change in shape of these surfaces due to wear will still be within the angle formed by the faces H and I, and consequently the force reacting through the wedge will still operate thereupon.

such a construction in OPQIiIlLlOIl, the T6210? InFig. '-l a modified construction is illustnted in which the friction members G and G are arranged upon opposite sides of an intermediate rotary member B and bear upon the surfaces H and H parallel to the plane of rotation and the surfaces I and I parallel to the axis. The wedge J is bifurcated to embrace the members G and G and will react thereon to force them against the surfaces It, H I, I.

In Fig. 5, another modification is illuS- trated, in which the friction members G G have their friction surfaces H parallel to the surface of the wedge J. W'ith this construction the device will first operate by transmitting the force from the Wedge in a direction perpendicular to the surface H and as the latter through use wears into grooves the force will be divided as in the construction illustrated in Fig. 2.

What I claim as my invention is:

1. The combination of a traveling friction element having stepped friction faces, a cooperating element comprising a shoe having correspondingly stepped faces, and a wedge movable thereon in a direction transverse to that of said traveling element.

2. The combination with a traveling friction element, having opposed stepped friction faces, of a cooperating element comprising a pair of shoes engaging said opposed faces and correspondingly stepped, and a Wedge intermediate said shoes.

3. The combination with a rotary friction element having stepped friction faces, of a cooperating element comprising a segmental shoe having a correspondingly stepped face, and a Wedge movable radially upon said 7 shoe.

4. The combination with a rotary friction element, having stepped annular friction faces, of a segmental shoe correspondingly stepped and engaging said rotary member, a wedge radially movable on said shoe, and a bearing upon Which said wedge is rockably supported.

5. The combination of a traveling friction element, a cooperating element forming in a efl'ect a bearing for the first-mentioned element, said cooperating element including a shoe and a Wedge, and means for transmitting an actuating force to said traveling element Within the angle of friction, said force efiecting a relative movement of the wedge and shoe in a direction transverse to the travel of said element, thereby clamping the shoe to the Wedge.

6. The combination of a traveling friction 7 element having singularly-arranged friction faces, a cooperating element forming in effect a bearing forthe first-mentioned element, said cooperating element including a shoe engaging said faces and a wedge engaging the shoe, and means for transmitting an actuating force to said traveling element within the angle of friction, said force effecting a relative movement of the wedge and shoe in a direction transverse to the travel of said element, thereby pressing the shoe simultaneously against both of said friction faces and clamping the Wedge to the shoe.

7. The combination of a traveling friction element having opposed friction faces, a cooperating element forming in effect a bearing for the first-mentioned element, said cooperating element including a pair of shoes operating element including a pair of shoes for engaging said opposed faces and a Wedge arranged intermediate the shoes, and means for transmitting an actuating force to said traveling element Within the angle of friction, said force effecting a relative movement of the wedge and shoes in a direction transverse to the travel of said element, thereby pressing the shoes in engagement with said opposed faces and clamping the shoes to the Wedge. V

9. The combination of a rotating friction member, a cooperating stationary element forming in eifect a bearing for the first-mentioned element, said cooperating element including a shoe and a Wedge, means for transmitting a force to said rotating friction element without the angle of friction, and means for transmitting a force to said rotating friction element within the angle of friction, said last-mentioned force effecting a relative movement of the wedge and shoe in a direction transverse to thetravel of said element, thereby clamping theshoe to the wedge.

10. The combination with a rotating friction element, of a shaft upon which saidelement is mounted, means for transmitting a force to said shaft Without the angle of friction, means for transmitting a force to said shaft within the angle of friction, and a 00- operating friction element forming a bear ing for the rotating friction element and actuated by a force Without the angle of friction, said cooperating friction element including a Wedge and a shoe, said force acting upon the shaft within the angle of friction effecting a relative movement of the wedge and shoe in a direction transverse to the axis of rotation of said rotating element, H

thereby clamping the shoe to the wedge.

11. The combination with a rotating fric-- cooperating friction elements forming a with said opposed friction faces and clampbearing for the rotating element When the ing the Wedge to the shoes. 1 latter is acted upon by the force Without the In testimony whereof I aflix my signature angle of friction, said force Within the angle in presence of two Witnesses.

5 of friction eifecting a relative movement of MAXIMILIAN J. L. TOWLER.

the wedge and shoes in a direction trans- Witnesses: verse to the axis of rotation of said element, 1 N ELLIE KINSELLA, thereby pressing the shoes in engagement HARRY WV. GALVIN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, I). G. n 

